Research has indicated that certain segments of the population (for example, young children and the elderly) may be more easily awakened from sleep through the use of a human voice annunciation in addition to or in place of a tonal pattern emitted from a life safety device including but not limited environmental condition detectors. Further, it has been shown that the use of a voice familiar to the sleeping person may even be more effective in awakening a person and alerting him or her to the presence of a potential hazard. Therefore, the use of life safety devices such as environmental condition detectors which emit a message using a familiar voice can be useful to help notify persons of the existence of potentially hazardous conditions in their environment. One way to accomplish this is to have a user familiar to other occupants of a dwelling or building equipped with an environmental condition detector unit record a verbal message of their own original content into an electronic memory of the detector unit to be played audibly upon the sensing of an environmental condition. One potential problem with this scenario is that the user recording the message may not record a message that is most helpful or safe to other occupants of the dwelling or building. In a worst case scenario, a user recording his or her own messages could further endanger the other building occupants by unknowingly providing dangerous instructions on how to respond to a sensed environmental condition. Since the specific factors surrounding each hazardous condition occurring in a dwelling or building are different, what may seem like reasonable directions to a particular person on how to respond to one hazardous situation may prove disastrous in another situation. For example, a person may choose to record instructions to open a window in response to the presence carbon monoxide to provide fresh air; however, if the same instructions were recorded as a response to the presence of fire, life threatening conditions could occur in certain situations. As another example, an ill-advised user could choose to record his or her own alarm tonal patterns or other sounds that could confuse other occupants of the dwelling or building who are accustomed to the tonal patterns which have specific meaning with respect to the type of condition that was detected. As another example, a well meaning parent could record a message for a child to wait in the child's bedroom until a parent comes to get them. When an unpredictable, hazardous condition occurs, the parent may not be home or may be unable to get to the child's bedroom causing increased risk to the child if the parent never arrives. In general, the common users of life safety devices, while they may have the best of intentions, quite often lack the requisite knowledge to give consistently appropriate instructions to others on how to remain safe in a potentially hazardous situation. This is particularly the case when a user records a message of their own content without any knowledge of the details of what a future hazardous situation may involve.
The various embodiments of the instant invention provide the desired alerting feature of a familiar voice during the detection of an environmental condition to effectively capture the attention or awaken other occupants of a dwelling or building while also providing the critical additional safety feature of not permitting unsafe instructions to be audibly broadcast to the occupants trying to deal with a potentially hazardous condition. Research has shown that young children are a significant part of the population who may benefit most by hearing a familiar voice during an emergency situation, especially while they are sleeping. Therefore, it is particularly important to limit messages in a familiar voice emitted during potentially hazardous situations to only messages with safe content since young children, in particular, will not likely have the ability to clearly decide how to safely respond themselves to a potentially life-threatening situation.